Henry middlebiiook crane



(No Model.)

H. M. CRANE. EARTH CONDUCTOR 0R GROUND WIRE ATTACHMENT.

Patented June 29, 1897.

fiibcesses Iuvenl'or.

/ m WWI/I ful adjunct to the protector-ground.

contiguous turns round the pipe and to at- NITED STATES PATENT Fries.

HENRY MIDDLEBROOK CRANE, OF BOSTON, MASSACHUSETTS, ASSIGNOR TO THEAMERICAN BELL TELEPHONE COMPANY, OF SAME PLACE.

EARTH CONDUCTOR OR GROUND-WIRE ATTACHMENT.

SPECIFICATION forming part of Letters Patent No. 58 5,185, dated June29, 1897.

Application filed May 10, 1897. Serial No. 635,873. (No model.)

To all whom it may concern.-

Be it known that-I, HENRY MIDDLEBROOK CRANE, residing at Boston, in thecounty of Suffolk and State of Massachusetts, have invented certainImprovements in Earth Conductors or Ground \Vire Attachments, of whichthe following is a specification.

The earth is employed in association with telegraphic, telephonic, andother kinds of electric circuits both as a return-conductor and as adischarge-conductor for lightningarresters and similar protectivedevices.

In either case it is customary and highly convenient to attach the wireleading from the circuit or protective'appliance to a metal gas or waterpipe, for by reason of the extensive ramifications of these pipes of gasand water systems a very large conductor-surface exposed to the crust ofthe earth is thus made available.

The necessity of a thoroughly-efficient connecting device especially inthe protector association, has lately become very manifest.

Prior to my invention the method of attaching the earth conductors tothe gas and water pipes has been to wind the copper wire in many temptthe formation ota homogeneous electrical union of the said pipe and wireby soldering.

Soldering is a difficult process in places where ordinarily ground-wireconnections have to be made, and experience shows that it is oftenslurred and imperfectly done, and in such cases this mode of connection,never thoroughly trustworthy, is very inferior and cannot be relied uponas a safe and success- The object of my invention is to provide asuitable connector for easily and conveniently attaching the ground-wireto the gas or water pipe, which connecting appliance shall also beperfectly trustworthy as a good electrical connection of low resistance,shall be perma nent in the perfection of its attachment, and shalllikewise be easily detached if disconnection is required.

My connecting appliance consists of a metal angle-piece with slots inone of its sides and a tapped hole, to which is fitted a tighteningset-screw, in the other. A strip of metal is attached by soldering orotherwise to the tapped side of the angle-piece, being tapped or slottedfor the passage of the screw.

The metal strip is preferably formed of tinned brass, and the bracket orangle-piece may be a punching and brass also.

To use such a connector in attaching the ground-wire to the pipe, thelatter is carefully cleaned and brightened, the strip of metal is 60passed round it and looped through the slots in the angle-piece. Onsetting up the screw the strip is drawn about the pipe as tightly asdesired, and an excellent and permanent electrical connection is made.The strip of 6 metal can be as long as may, in each individual case, beconvenient, and the ground-wire is secured to it by riveting orsoldering or by a binding-screw, as preferred.

Of course all screws employed in this form 7 o of connection may befitted with jam-nuts.

' In the drawings accompanying this specification, Figure 1 shows theconnecting appliance with the brass strip looped through the slots ofthe angle-piece, the conductingwire being brazed or soldered thereto.Fig.

2 is a View of the same applied to a gas or water pipe and provided witha bindingscrew attachment for the conducting-wire. Fig. 3 is aperspective view of the bracket or angle-piece detached; and Fig. 4represents a portion of an electric circuit provided with protectiveapparatus, the ground-wire and connecting appliance of my inventionbeing clearly shown.

A is the conductor-connecting appliance; B, its bracket or angle-piecehaving slots at and b and a set-screw S, preferably supplied with ajam-nut s.

R is the strip of brass or other metal or alloy soldered, brazed, orotherwise attached to the said angle-piece and slotted or perforated forthe passage of the screw S.

In a connecting appliance or grounding attachment of this class forpipes which I have made the end of the strip is doubled back on itself,soldered to the outer surface of the unslotted face of the bracket,andthen passed over the point of the set-screw and threaded through theslot at in the other face or close I00 to the apex of the angle of saidbracket.

The earth conductor or ground-wire to may be soldered orbrazed to theend of the metal strip .R, as at so, or, if desired, the latter may beprovided with a binding-screw C, preferably furnished (like theset-screw S) also round the pipe, drawn again through the same slot areversely, and then' baekwardly through the second slot 1) of :theangle-piece and bent backward therefrom. This being done it only remainsto set or turn up the screw S, when the brass strip is stronglytightened up around the pipe and an excellent'eleetrical connection withthe said pipe is thus provided. The position of the screw may then beseen red by the jam-nut .9. If a soldering connection is wanted for thegroundwire 11', it may, if desired, be made before the connector isapplied to thepipe, and so made will'avoid the chance of poor work dueto inaccessibility.

In Fig. l, \V is the conductor of the main circuit and is shown asleading through a fuse-protector jand a plate and air space thewater-pipe P, to which it is attached by means of the connectorappliance A,which connects with the wire w through the binds ing-screw Oand with the pipe 1 through the metal strip R, angle-piece 13, andset-screw S, constituting the said appliance A.

The arrangement is very efficient, almost the entire circumferentialsurface of the pipe being in contact with the metal strip, thus making afirst-class electrical connection and preventing the ingress of moistureand the resulting corrosion, which otherwise might be expected. Theconnector has but three essential parts, all of which are simple,inexpensive, and easily made, and it can be attached without taking itapart, thus not only facilitating the process of attachment, butavoiding the chance of the parts loosening or being lost.

I am aware that grounding clamps or connectors, broadly considered, arenot new, and I consequently make no claim to such a device per 3c; but

I (10 claim- 1. A connectorfor attaching a ground-wire, or an electriccircuit or protector earth conductor, to a gas or water pipe, consistingof a metal angle-piece having slots as described, and a threadedperforation through one of its faces; a metal strip secured at one endto the outside of the perforated face, arranged to pass twice inopposite directions through the first slot, and once through the other,and adapted to surround the said grounding-pipe between the pointspassing the said first slot;

and a tightening set-screw associated with the threaded perforation ofthe said anglepiece, and impinging upon the metal strip between itsfixed end and the nearest slot thereto, substantially as set forth.

2. he combination with the ground or earth wire ofan electric circuit orprotective device; and a metal pipe or red in permanent earthconnection, such as a gas or water pipe; of an attachment comprising ametal bracket or an gle-piece having slots as described in one of itssides,and ascrew-threaded hole through the other, a metal strip at oneend secured to the said angle-piece, andits other end. to theground-wire, and arranged to pass through the-first slot and back, andthen through the second, successively, and to embrace the said rodorpipe by that portion of its length be tween the said two passages of thefirst slot; together with a tightening-screw passing through thethreaded hole of said an gle-piece,

and adapted to bear atits point on the said strip; the said attachmentforming the terminal of the said earth-wire, and constituting a convenienrly-applied and efficient electrical connection betweenthe saidearth-wire and the said permanently-grounded pipe or rod;

substantially as and: forthe purposesspecitied.

. A connectorforattaching an electric conductor to a gas or otherpipe,consisting of a bent or curved metal base slotted as described, andprovided with a tightening-screw at one end thereof, a metal band fixedby one end to the said base, and extended over the point of said screwthrough the first of said slots, backwardl y and forwardly insuccession, and adapted to be returned through the second slot, and tobe secured over the end of the base, as and for the purpose set forth.

4. A connector for attaching an electric conductor to a gas or otherpipe, consisting of a metal band looped around the pipe, in combinationwith a holding or securing device through which said loop passesandwhereby it is held in close contact with the pipe, substantially asdescribed.

In testimony whereof I have signed my name to this specification, in thepresence of two subscribing witnesses, this 3d day of May, 1897.

HENRI )iIllDLliliIlOOK CRANE.

\Vitnesses:

JosEPH A. GATELY, Tnonas D. Lockwooo.

